Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with hierarchical micro- and nano-scale features consisting of two-dimensional periodic pores. In this paper, we present an innovative label-free optical sensor based on a biological-plasmonic hybrid nanostructure by self-assembling silver (Ag) nanoparticles into diatom frustules. The photonic-crystal-like diatom frustules provide a spatially confined electric field with enhanced intensity that can form hybrid photonic-plasmonic modes through the optical coupling with Ag nanoparticles. The experimental results demonstrate 4-6x and 9-12x improvement of sensitivities to detect the Raman dye for resonance and nonresonance SERS sensing, respectively.

Date Published: 13 March 2014
PDF: 7 pages
Proc. SPIE 8933, Frontiers in Biological Detection: From Nanosensors to Systems VI, 89330J (13 March 2014); doi: 10.1117/12.2042429

Published in SPIE Proceedings Vol. 8933:
Frontiers in Biological Detection: From Nanosensors to Systems VI
Benjamin L. Miller; Philippe M. Fauchet; Brian T. Cunningham, Editor(s)